"For me, it's (taking) the double teams to make sure they can fly around, make sure they can run from sideline to sideline freely, make big plays," Sagapolu said.

He'll be facing a lot of double teams again this season given that depth is especially a concern on the ends.

Projected starter Garrett Rand (torn Achilles tendon) is out for the year. The other likely starter, promising sophomore Isaiahh Loudermilk, is sidelined while he rehabs from offseason left knee surgery. Loudermilk hopes to be ready when Big Ten play begins in late September.

That leaves redshirt freshman Kayden Lyles, who was just move from offensive to defensive line at the beginning of camp, as one of the potential starters next to Sagapolu. Another redshirt freshman, walk-on Matt Henningsen, has been impressing at practice.

There is a little more experience at outside linebacker , where Andrew Van Ginkel at least played a key role off the bench last season to spell starters Garret Dooley and Leon Jacobs. Juniors Zack Baun and Tyler Johnson also have some experience as reserves.

"It's not necessarily that they have to learn the defense. They have to get used to their new roles as starters and playing more," Connelly said.

Dixon is the lone starter back in the secondary, though the Badgers do have Dontye Carriere-Williams returning at cornerback. The sophomore started five games and often served as the nickelback.

There is at least speed on the back end. And the young cornerback group can get tested in practice by a deep receiving corps that had similar turnover a year ago.

Lacking experience at wideout, Chryst and his staff ended up developing a productive quartet. Now, the position is a strength with juniors Quintez Cephus and A.J. Taylor, along with sophomores Danny Davis and Kendric Pryor.

"Certainly there's a comfort when you have returning starters, but there is also kind of an excitement and natural progression. I've never been part of a program where everyone returned," Chryst said.

There is one more certainty on defense: Jim Leonhard is back for his second season as coordinator and third overall on the staff overseeing the secondary. That's important for a team that has had turnover at coordinator before Leonhard with Justin Wilcox in 2016 and Dave Aranda leaving after the 2015 season following a three-year stint.

Leonhard has also had a good track record developing defensive backs.

"Camp is a great time," Chryst said. "You have an opportunity to define a role, and the best thing you want to do if you want to play a lot is to play really well."